7TH  Heaven By James Patterson and Maxine Paetro. 
Discover the Women's Murder Club's most terrifying case ever.   As a terrible series of fires blazes through California, the heat begins to rage too close to home.  A terrible fire in a wealthy suburban home leaves a married couple dead and Detective Lindsay Boxer and her partner Rich Conklin searching for clues. And after California's golden boy Michael Campion has been missing for a month, there finally seems to be a lead in his case-a very devastating lead.  As fire after fire consume couples in wealthy, comfortable homes, Lindsay and the Murder Club must race to find the arsonists responsible and get to the bottom of Michael Campion's disappearance. But suddenly the flames are raging too close to home.